Dart - Collections

void main() {
      // creating a new empty List
      List geekList = [];
    
      // Adding an element to the geekList
      geekList.addAll([1, 2, 3, 4, 5, "Apple"]);
      print(geekList);
    
      // Looping over the list
      for (var i = 0; i < geekList.length; i++) {
            print("element $i is ${geekList[i]}");
      }
    
      // Removing an element from geekList by index
      geekList.removeAt(2);
    
      // Removing an element from geekList by object
      geekList.remove("Apple");
      print(geekList);
    
      // Return a reversed version of the list
      print(geekList.reversed);
    
      // Checks if the list is empty
      print(geekList.isEmpty);
    
      // Gives the first element of the list
      print(geekList.first);
    
      // Reassigning the geekList and creating the
      // elements using Iterable
      geekList = Iterable<int>.generate(10).toList();
      print(geekList);
}

void main() {
    // Initializing the Set and Adding the values
    Set geekSet = new Set();
    geekSet.addAll([9, 1, 2, 3, 4, 5, 6, 1, 1, 9]);
    
    // Looping over the set
    for (var el in geekSet) {
        print(el);
    }
    
    // length of the set.
    print('Length: ${geekSet.length}');
    
    // printing the first element in the set
    print('First Element: ${geekSet.first}');
    
    // Deleting an element not present. No Change
    geekSet.remove(10);
    
    // Deleting an element 9
    geekSet.remove(9);
    print(geekSet);
}

import 'dart:collection';

void main() {
    // Create a new HashSet
    var set = HashSet<String>();
    
    // Add some elements to the set
    set.add('apple');
    set.add('banana');
    set.add('cherry');
    
    // Check if an element is in the set
    print(set.contains('apple')); // Output: true
    print(set.contains('pear')); // Output: false
    
    // Iterate over the set
    set.forEach((element) {
        print(element);
    });
}

void main() {
    // Initializing the map with sample values.
    var geekMap = {1: "Apple", 2: "Mango", 3: "Banana"};
    print(geekMap);
    
    // Adding elements by different methods.
    geekMap.addAll({4: 'Pineapple', 2: 'Grapes'});
    geekMap[9] = "Kiwi";
    print(geekMap);
    
    // printing key and values
    print('Keys: ${geekMap.keys} \nValues: ${geekMap.values}');
    
    // removing an element from the map by its key
    geekMap.remove(2);
    
    // printing the map and its length
    print('{$geekMap} length is ${geekMap.length}');
}

import 'dart:collection';

void main() {
    // Create a new HashMap
    var map = HashMap<int, String>();
    
    // Add some key-value pairs to the map
    map[1] = 'one';
    map[2] = 'two';
    map[3] = 'three';
    
    // Access the value for a specific key
    print(map[1]); // Output: one
    
    // Iterate over the map
    map.forEach((key, value) {
        print('$key: $value');
    }); 
}

import 'dart:collection';

void main() {
    // Initializing the Set and Adding the values
    // We can also initialize a queue of a specific type
    // as Queue<int> q = new Queue();
    var geekQueue = new Queue();
    geekQueue.addAll([9, 1, 2, 3, 4, 5, 6, 1, 1, 9]);
    
    // Adds Element to the Start of the Queue
    geekQueue.addFirst("GFG");
    
    // Adds Element to the End of the Queue
    geekQueue.addLast("GFG2");
    print(geekQueue);
    
    // Removes the first Element
    geekQueue.removeFirst();
    print(geekQueue);
    
    // Removes the Last Element
    geekQueue.removeLast();
    print(geekQueue);
    
    // printing the first element in the set
    print('First Element: ${geekQueue.first}');
    
    // Looping over the set
    for (var el in geekQueue) {
        print(el);
    }
    
    // Other Operations
    // length of the set.
    print('Length: ${geekQueue.length}');
    
    // Deleting an element not present. No Change
    geekQueue.remove(10);
    
    // Deleting an element 9
    geekQueue.remove(2);
    print(geekQueue);
}

// Dart Program to Implement
// Doubly Linked List
import 'dart:collection';

// Class that extends LinkedListEntry.
// Each item in the LinkedList will be
// an instance of this class.
base class Box extends LinkedListEntry<Box> {
    final String contents;
    final int number;
    
    Box(this.contents, this.number);
}

void main() {
    final myLinkedList = LinkedList<Box>();
    
    // Adding elements to the LinkedList
    myLinkedList.add(Box('First Box', 1));
    myLinkedList.add(Box('Second Box', 2));
    myLinkedList.add(Box('Third Box', 3));
    
    // Iterating over the LinkedList
    for (final box in myLinkedList) {
        print(" ${box.contents} , ${box.number}");
    }
    
    // Remove an element from the LinkedList
    final boxToRemove = myLinkedList.firstWhere(
        (box) => box.contents == 'Second Box',
    );
    boxToRemove.unlink();
    
    print('');
    
    print('After removal:');
    for (final box in myLinkedList) {
        print(" ${box.contents} , ${box.number}");
    }
}